Transcript Hormones - Capital High School

Hormones
Topic B6
Production and function (B.6.1)
primarily chemical
messengers
produced in endocrine
glands
secreted directly into
bloodstream and
transported to various
organs, tissues, or cells
in the body
have a variety of functions
– adrenaline
produced in the adrenal glands
the ‘fight or flight’ hormone
stimulant
– dilates pupils and airways, increases heart beat and the
release of sugar into the bloodstream
– thyroxine
produced in the thyroid gland
regulates the body’s
metabolism
– insulin
protein (51 amino acids) produced in the pancreas
regulates blood sugar by
– triggering cells to uptake sugar
– stimulating the liver to store glucose in the form of
glycogen
diabetics produce too little insulin
Compare structures of cholesterol and
sex hormones (B.6.2)
all contain a steroid backbone consisting
of three six-membered rings and a fivemembered ring fused together
but they differ in the type and position of
substituents (functional groups) on the
steroid backbone
Male
Female
cholesterol
Oral contraceptives (B.6.3)
most commonly used is called the
combined oral contraceptive pill
– contains a combination of estrogen and
progesterone
– mimics pregnancy by keeping hormones at
high levels
prevents ovulation from occurring
makes the lining of the uterus thinner so that it is
unsuitable for implantation of a fertilized egg
makes the mucus in the cervix thicker to prevent
sperm from reaching the egg
Use and abuse of steroids (anabolic)
(B.6.4)
several steroids that resemble testosterone have
been synthesized
use
– promote increased muscle mass and growth
– can be given following injuries to rebuild
muscle
abuse
– can enhance athletic performance
taking large doses cause harmful side
effects
– in men: impotence, baldness, problems in
urinating, smaller testes
– in women: changes in secondary sex
characteristics, build up of muscles and
increased facial hair
– both men and women also experience
• violent temper/aggressive behavior
• liver tumors, high blood pressure and heart attacks